Our objective is to delineate the utility of established in vitro human prostatic adenocarcinoma cells as a new model for studies on etiology, biology, detection and therapy of human prostatic neoplasia. The subject of this study will be the cell line LNCaP which we isolated from a metastatic lesion of human prostatic cancer (CaP). The cultured cells are epitheliod and closely resemble cells from the parental tumor. The malignant properties of LNCaP cells are maintained: nude mice develop adenocarcinomas at the injection site. Chromosomal analysis of LNCaP cells shows an aneuploid human karyotype with several characteristic marker chromosomes. The unique property of the LNCaP cell line is the continuous production of acid phosphatase which is biochemically similar and immunologically identical to human prostatic acid phosphatase (PAP). The LNCaP cells in culture will be characterized as to their growth parameters and responsiveness to growth modulators such as serum, hormones, growth factors, and antineoplastic drugs. Markers characteristic of prostatic neoplastic epithelium (enzymes, hormonal receptors, zinc) will be monitored. Prostatic acid phosphatase secreted in vitro by the LNCaP cells will be purified in order to produce in goats and rabbits specific antisera. In nude mice the rates of tumor growth will be studied and correlated with hormonal manipulations and treatment with drugs used in clinical management of CaP. The levels of biochemical and immunological markers of LNCaP cells in the plasma of tumor bearing animals will be measured. Localization in tumors of radiolabeled antibodies against PAP will be assessed.